In conventional industrial engine system, a cylinder liner is mounted in the cylinder of engine and adapted to prevent inner surface of the cylinder from wearing caused by a piston reciprocating in the cylinder. The inner surface of the cylinder liner which contacts with the piston is smoothly honed by honing machine. The inner surface of the cylinder liner is provided with a plurality of parallel recess lines which are filled with lubrication oil for lubricating interface between the inner surface of the cylinder and the outer surface of the piston reciprocating in the cylinder liner. All recess lines are intersected to form a plurality of diamond shapes. Generally, each of parallel recess lines is hatched by a hatch angle cross honing process, and cross angle of the recess lines which are intersected is 30 to 60 degrees. As the recess lines of the cylinder liner are filled with lubrication oil, the frictional resistance between the piston and the cylinder liner is reduced when the piston is reciprocated in the cylinder.
However, because the inner surface of the cylinder liner which is provided with a plurality of diamond-shaped recess lines has relatively low roughness of 0.8 to 2.2, the recess lines are easily worn out. Additionally, as the recess lines are lowered and the edges of the recess lines are sharpened, a plurality of diamond-shaped surfaces formed by the diamond recess lines are easily worn by the piston which is reciprocated in the cylinder liner.
As the recess lines is shallower and the lubrication oil is reduced, the lubrication oil is not sufficiently supplied and distributed onto the inner surface of the cylinder liner. Therefore, the piston is not smoothly reciprocated in the cylinder, the engine performance is not good, and also the cylinder liner has a short life time.